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A Biggeri

Publications and source records attributed to A Biggeri.

At least 55 records · Page 3Linked to original sources
PubMed1995

Characterisation of aberrant crypt foci in carcinogen-treated rats: association with intestinal carcinogenesis.

Carcinogen-treated rats develop foci of aberrant crypts in the colon (ACFs) that have been interpreted as preneoplastic lesions. To characterise ACFs further, we studied in the unsectioned colon of rats the number, multiplicity, some morphological characteristics and the type of mucin production in ACFs. In ACFs observed 115 days after the administration of 50 mg kg-1 1,2-dimethylhydrazine (DMH), crypt multiplicity [number of aberrant crypts (AC) per focus] was positively correlated (P < 0.0001) with the reduction of goblet cells, and with luminal and nuclear alterations in the cells surrounding the lumen of the ACs. We studied mucin production in the unsectioned colon, demonstrating that ACFs producing sulphomucins (like the normal distal rat colon) were progressively reduced when ACF multiplicity increased, whereas ACFs containing sialomucins (correlated with an increased risk of colon cancer) or both sulphomucins and sialomucins increased with crypt multiplicity. We also studied ACFs in the colon and the occurrence of intestinal tumours in rats treated with azoxymethane (AOM; 64 mg kg-1). A significant association was found (P = 0.04) between tumours and the presence of 'large' ACFs (AC/ACF > 14 crypts) and a borderline significant association (P = 0.057) between the presence of tumours and sialomucin-producing ACFs. We found no association between the number of ACFs, ACF multiplicity and the presence of tumours.

1,2-Dimethylhydrazine↗
PubMed1995

Squamous cell carcinoma arising in vulval lichen sclerosus: a longitudinal cohort study.

Histological changes of lichen sclerosus (LS)--a chronic inflammatory disease--are frequently found in association with squamous cell carcinoma (SCC) of the vulva, suggesting that women with this disorder are at increased risk. However, follow-up studies have been less convincing, showing that the vast majority of these patients do not go on to develop cancer. In this study, a series of 211 women affected by histologically demonstrated vulval LS were treated with topical therapy (testosterone, clobetasol) and followed prospectively by repetitive vulval examination. Three patients developed SCC of the vulva (two invasive, one in situ) at the sites affected by LS during an average follow-up period of 1 year and 8 months. Compared with the reference population, the number of cases of invasive SCC detected significantly exceeded the number estimated to occur in a comparable age-matched group. The standardized incidence rate of vulval SCC in the LS cohort was 317 (95% CI 35.7-1146.2). Cumulative risk was 14.8% (0.06% in the general female population), with a relative risk of 246.6. In conclusion, these data support the view that LS is a precursor of SCC, although characterized by slight tendency to evolve to carcinoma. Medical treatment of LS, although useful in the control of severity of disease, did not seem to be able to prevent the evolution to malignancy.

Administration, Topical↗
PubMed1995

Episodes of care for first-ever psychiatric patients. A long-term case-register evaluation in a mainly urban area.

BACKGROUND: Psychiatric case registers (PCRs) are particularly useful for studying patterns of care over time. Methods of 'survival analysis' have rarely been used for assessing such data. METHOD: A longitudinal study was conducted over 10 years (1 January 1982 to 31 December 1991) on 1423 first-ever psychiatric patients, using the PCR of South Verona, Italy. The product-limit method, the log-rank test, the Cox regression model and the Poisson regression analysis were used to analyse episodes of care and relapses. RESULTS: The duration of the episodes of care increased consistently from the first to the fifth episode. The probability of opening a new episode of care after the first one increased consistently from the second to the sixth episode. The only variable significantly associated with the length of the first episode of care was diagnosis (highest probability of having longer episodes for schizophrenic patients), while the length of the breaks following the first episode of care was associated with diagnosis, sex and occupational status (highest probability of opening a second episode of care for schizophrenic subjects and those with alcohol and personality disorders, for males, and for unemployed patients). The probability of opening a new episode of care decreased with time since last contact and increased with number of previous contacts. CONCLUSIONS: The community psychiatric service in South Verona is fulfilling its original aim, that is, to give priority to the continuity of care for patients with chronic and severe mental illnesses. Survival analyses proved to be useful methods for assessing episodes of care.

Adolescent↗
PubMed1995

[The analysis of the spatial aggregation of health events using risk surface density estimation methods].

Methods for the analysis of the spatial aggregation of health events has received growing attention under the pressure of public opinion concern and as tools for the identification of potential risk sources, for monitoring relevant geographical areas and, finally, for public health decisions. The development of statistical methods for the detection and localization of spatial clusters has mainly concerned individual data. This paper is aimed at describing one of the methods proposed for the identification of clusters in the case of information at individual level and at presenting its extension to grouped data. This method, the surface density estimation method using the Kernel approach, offers remarkable advantages in terms of simplicity of implementation and flexibility, this latter being an extremely important characteristic in the case of exploratory analyses. For exemplification purposes, the density estimation method has been applied to individual data concerning the spatial distribution of cerebral tumors in Campi Bisenzio (FI) and to the distribution of gastric cancer mortality in the municipalities around Arezzo and Pesaro.

Brain Neoplasms↗
PubMed1995

[A critical review of epidemiological methods for spatial analysis].

Since the 1950's a number of methods have been developed whose aims is to provide enhanced mapping tools, which allow the depiction of the distribution of disease, and thereafter, to assess risks due to environmental factors (or other spatial-defined factors). Our review of statistical-epidemiological methodology for spatial analysis of diseases shall outline the distinction between global tests for clustering (detection of non casual distribution of events in an area) and cluster detection's techniques for the identification and location of abnormal aggregation of disease's cases. In this paper we evaluate each-one of the proposed methods, on general grounds, with regard to whether they meet the aims of the analysis and how successful they are in overcoming problems.

Epidemiologic Methods↗
PubMed1995

[Case-control studies to assess relative risk in proximity of putative sources of environmental pollution].

This paper discusses the analysis of the disease risk as function of distance from prespecified exposure sources. Instead of the usual ecological framework, the proposed model is based on individual data and includes the major individual risks factors as covariates. The risk due to environmental exposure is modelled using excess relative risk as effect measure, while the effect of individual risk factors is modelled using relative risk. A case-control design is proposed to fit this model and to obtain effect estimates.

Case-Control Studies↗
PubMed1995

[Comparison of epidemiologic methods in a case-control study of lung cancer and air pollution in Trieste, Italy].

To investigate the relationship between air pollution and histologic type of lung cancer we conducted a case-control study among deceased men in Trieste, Italy. 755 cases of lung cancer and 755 controls were identified through the local autopsy registry. Information on smoking habits, occupation and place of residence was obtained from the subject's next-of-kin. Air pollution at the residence of each subject was estimated from the average value of total particulate at the nearest monitoring station. Spatial models and logistic regression were used to evaluate the effect of residence and air pollution on LC after adjustment for age, smoking habits, likelihood of exposure to occupational carcinogens and social group. The risk of lung cancer increased with increasing level of air pollution for all types of lung cancer combined (P = 0.022), for small cell carcinoma (P = 0.016) and for large cell carcinoma (P = 0.049). Compared with inhabitants of the residential area, residents of the rural area had a relative risk (RR) of 0.6 (95% confidence interval (CI): 0.4-1.0). The RR was 1.5 (1.0-2.2) for residents of the center of the city and 1.4 (1.0-2.1) for residents of the industrial area. In the center of the city the excess risk was almost completely restricted to small cell carcinoma (RR = 2.0) and to large cell carcinoma (RR = 2.6). In the industrial area the risk was increased especially for adenocarcinoma (RR = 2.1). These results provide evidence that air pollution is a moderate risk factor for certain histologic types of lung cancer.

Adenocarcinoma↗
PubMed1995

Incidence of silicosis among ceramic workers in central Italy.

The incidence of radiological silicosis was studied among 2480 male workers employed in the ceramics industry. The subjects entered the surveillance program during 1974-1987 and were followed through 1991 with annual chest radiographs. The cumulative risk of silicosis (1/1 or greater; p,q,r) reached 48% (95% confidence interval 41.5-54.9) after 30 years of employment. In a multivariate Cox's proportional hazards model, the effect of duration of exposure increased linearly up to the category of 25-29 years; an extremely high hazard risk of 14.6 was found among those with 30 years or more of exposure in comparison with those employed 10 years or less. Smoking habit also significantly contributed to the model, although its role in the biological process is unclear. In conclusion, exposure to silica dust has been associated with a high incidence of silicosis among ceramics workers. The risk estimates are consistent with the recent findings of silicosis incidence among South African gold miners.

Adolescent↗
PubMed1994

Dietary carbohydrates modify azoxymethane-induced intestinal carcinogenesis in rats.

The effect of different dietary carbohydrates (sucrose, cornstarch and high amylose cornstarch) on intestinal carcinogenesis was studied in male Sprague-Dawley rats treated subcutaneously with azoxymethane (AOM) at a weekly dose of 8 mg/kg body wt for 8 wk. The diets, high in fat and low in calcium and fiber, were fed during and after AOM treatment. The number of colonic adenomas per rat in the groups fed either starch was lower (P < 0.05) than the number in the sucrose-fed rats [1.06 +/- 0.38, 0.30 +/- 0.10 and 0.41 +/- 0.22 (mean +/- SEM), in the sucrose-, cornstarch- and high amylose cornstarch-fed groups, respectively]. The incidence of total intestinal tumors (adenomas + adenocarcinomas) was not affected by dietary treatment. However, the incidence of tumors in the small intestine of the rats fed the two cornstarch diets tended to be slightly lower than for rats fed the sucrose diet (P = 0.075). Adenoma dysplasia and adenocarcinoma differentiation were similar among the rats fed the three diets. However, the adenocarcinomas in the rats fed the cornstarch diet were significantly smaller than those in the rats fed sucrose [0.99 +/- 0.14 cm2 (n = 13), 0.56 +/- 0.14 cm2 (n = 13) and 0.55 +/- 0.17 cm2 (n = 9) in rats fed the sucrose, cornstarch and high amylose starch diets, respectively]. Moreover, in the rats fed the cornstarch diet, the adenocarcinomas showed lower invasive potential than those in rats fed the sucrose diet. The results suggest an overall inhibition of AOM-induced carcinogenesis in rats fed the cornstarch diets.

Adenocarcinoma↗
PubMed1994

Incidence of cutaneous melanoma in the centre of Italy: anatomic site distribution, histologic types and thickness of tumour invasion in a registry-based study.

The majority of epidemiological data on cutaneous melanoma (CM) derives from studies carried out in a predominantly fair-skinned population. On the contrary, little is known of the epidemiological figures (including incidence data) in mediterranean populations. The aim of this study was to investigate the incidence rates of CM in a geographically-defined area of the centre of Italy, with particular attention to anatomic site distribution, histologic types and thickness of tumour invasion. After revision of the data base of the Tuscany Cancer Registry concerning the period 1985 to 1987, 282 incident cases of invasive CM (135 males, 147 females) were found in a resident population of 1,174,121 inhabitants. The mean annual age-standardized rates were 6.7/100,000 for males and 7.0/100,000 for females. Site-specific incidence rates showed an almost three-fold higher incidence of CM of the trunk in males than females (3.7/100,000 vs 1.4/100,000). Conversely, a four-fold higher incidence in females than in males was observed for the lesions of lower limb (2.1/100,000 vs 0.5/100,000). A statistically significant difference of incidence rates was also observed for the thigh (females 1.1/100,000, males 0.2/100,000), a normally sun-exposed area. Concerning histologic types of CM, the incidence of the nodular type was higher in males than in females (1.8/100,000 vs 1.3/100,000), even if the difference was not statistically significant in any class of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

National diabetes programs. Application of capture-recapture to count diabetes?

OBJECTIVE: To evaluate the utility of capture-recapture methods using multiple, routinely collected, computerized data sources to estimate the numbers and prevalence of diabetes. Methods employed for regional and national monitoring of diabetes have been too inaccurate or too expensive. RESEARCH DESIGN AND METHODS: A survey was undertaken that used four sources of ascertainment to identify prevalent cases of known diabetes in community of Northern Italy: diabetic clinic and family physicians, hospital discharges, prescriptions, and reagent strips and insulin syringes. Capture-recapture methods were employed to estimate the number of missing cases and to adjust for undercount to accurately estimate the number of people who had diabetes. RESULTS: We identified 2,069 unique prevalent cases of known diabetes with the intensive case-finding procedure. The diabetic clinic and family physicians data source identified the largest number of cases. The evaluation of the two sample capture-recapture estimates showed that they were all biased downward because of dependencies between sources. Log-linear modeling was employed to take into account the dependence among all data sources and the heterogeneity of diabetic patients. This method estimated that 2,586 cases existed, resulting in an ascertainment-adjusted prevalence of 2.77% (95% confidence interval, 2.44-3.10). Thus, despite the active case identification, approximately 20% could not be identified. However, the number of cases and rates could easily be adjusted using capture-recapture. CONCLUSIONS: The study shows that a two-sample capture-recapture estimate could be very biased if the investigator is not assured that the sources are independent. However, if at least three data sources are employed, log-linear models allow estimation of the number and prevalence rate adjusted for the degree of undercount (in spite of both the dependence of data sources and the heterogeneity of the diabetic population). The critical factor, however, is that the application of multiple sources with capture-recapture methods could be applied across broad geographical areas and across time to have cost-effective monitoring of diabetes at local and national level.

Adolescent↗
PubMed1993

A quality control system involving peer review of abnormal cervical smears.

An internal quality control system which is used in the centralized cytology laboratory of a population-based cervical cancer screening programme in Florence is described. It includes a peer review procedure. Abnormal cervical smears are circulated among all the cytologists and a consensus on the final diagnosis is reached. This daily procedure is designed to evaluate the performance of each cytologist and of the laboratory as a whole but can also be considered a valuable training opportunity. During an 18-month period 1197 smears were reviewed by 15 readers using a reporting form with six main categories of reporting (from 'negative' to 'invasive carcinoma'), plus an 'unsatisfactory' category. Overall the concordance between the 15 cytologists, assessed using the kappa statistic (range 0.46-0.71; median 0.60), was good. The level of agreement increased when a weighted kappa statistic (range 0.55-0.78; median 0.68) was used. Kappa values were also calculated for specific categories and suggested an increasing concordance with increasing severity of the lesions, the categories of 'severe dysplasia' and 'invasive carcinoma' showing the highest agreement. The poor results for the 'moderate dysplasia' confirmed the need for combining this group with the 'severe dysplasia', as proposed in the Bethesda system.

Female↗
PubMed1992

A cross sectional survey on breast self examination practice, utilization of breast professional examination, mammography and associated factors in Romagna, Italy.

In 1988, a cross-sectional survey was carried out in the Romagna region (Italy) to evaluate the association between knowledge of breast pathophysiology and preventive attitudes and screening tests practice for breast cancer. A self-administered questionnaire was distributed to a sample of asymptomatic women aged 20-64 years living in the city of Faenza (Northern Italy). Of the 657 responders, 58% reported that they practiced breast self-examination; 55% had had a professional breast examination, and only 9% had had a mammogram as a screening test. Logistic regression analysis (including variables such as age, education, employment) was performed to explore the relationship between screening tests practice and factors associated with their use. Breast self-examination practice (n = 590) was associated with preventive attitudes (aOR = 1.67, 95% CI = 1.09-2.53) and with a positive history of breast disease (aOR = 3.48, 95% CI = 1.72-7.04). Professional breast examination (n = 480) was related to preventive attitudes (aOR = 2.37, 95% CI = 1.51-3.71), knowledge of breast pathophysiology (aOR = 2.07, 95% CI = 1.31-3.28), and use of oral contraceptives (aOR = 1.81, 95% CI = 1.12-2.91). Mammography use (n = 540) was associated with preventive attitudes (aOR = 3.08, 95% CI = 1.40-6.76). The results show an inadequate utilization of screening tests in our population. Breast self-examination is strongly related to a positive history of breast disease, and this could reflect the lack of health educational programs aimed at the general population.

Adult↗
PubMed1990

Risk of breast cancer subsequent to proven gross cystic disease.

3809 women in whom breast cysts were aspirated were followed up to evaluate the observed/expected ratio of subsequent breast cancer. Breast cancer at cyst aspiration was excluded by physical examination and mammography. The first year of follow-up was censored to avoid a prevalence screening effect. Subsequent breast cancers were found either directly or by means of a cancer registry which also provided the expected age and residence specific incidence rates. The number of expected cancers was assessed in person-years (15,915 in the total series). The observed/expected subsequent breast cancer ratio was 1.77 (34/19.15; 95% confidence interval 1.23-2.48, P less than 0.05). The presence of gross cysts was associated with a moderately though significantly increased risk of subsequent breast cancer. Increased surveillance in such patients is not justified.

Adolescent↗
PubMed1990

[Analysis of temporal distribution of suicides. Methodological notes on comparison of dates of death and dates of suicidal act].

The short-term temporal cycles in the frequency of suicide for the Province of Florence 1985-1987 has been analyzed. The authors initially present a comparison between the Date of Suicidal Act and the recorded Death Certificate Date. In their data the difference, still debated in the literature, appears of no practical importance. The results show that suicides peak on Spring and Fall, with a temporal variation with regard to the first decade of the month, high at the beginning and low at the end. No evident pattern has been explained by day of the week, unlikely any reports from the literature. On the contrary, the effect of the National Holidays are striking, showing a decrease on the holidays and a sharp rise on the subsequent day.

Death Certificates↗
PubMed1990

[Mortality according to the birthplace in a Turin longitudinal study].

Mortality 1981-85 in the Turin Longitudinal Study population, 25-74 years old, was analyzed according to selected geographic areas of birth and socioeconomic status. People born in the Southern Regions and in the Isles, when compared with people ever resident in Turin, have low mortality from malignancies and accidents and in general from all causes of death but respiratory diseases. People born in the North-Eastern Regions have high mortality, mainly due to malignancies, and respiratory and digestive diseases. Such differences are stronger among men in low socio-economic status and tend to weaken with time from migration.

Adult↗
PubMed1989

[Spatial identification of an excess of cerebral tumors in a highly industrialized small area: results of a case-control study].

A case-Control Study for the association between Central Nervous System Malignancies and residence in a small area within the municipality of Campi Bisenzio (Florence, Italy) has been performed following a spontaneous reporting of three cases of brain cancer. All incident cases of SNC tumours diagnosed in the period 1973-82 with histological or radiological confirmation among residents in the study area are recruited as cases. Five controls for each case, matched by sex and age (+ - 1 year), are randomly chosen from demographic files in the municipality. The residential history for each subject enrolled in the study is recorded from the same demographic files. The relative risk for ever resident in the 46-50 electoral sections relative to never resident was 7.33 (C.I. 95% 2.6-20.3). A trend for duration of residence was also relevant (less than 5 years RR = 2.1, 5-10 years RR = 8.4, more than 10 years RR = 11.3; chi-square for trend = 41 p = 0.00002).

Adolescent↗